I would go ahead and order it. Oem boards rarely list tested ram, unless your alienware board is an over the counter board which you can check on the manufacturer's website in the memory QVL download. Newegg and frys are great places to order ram. I prefer frys stores as they won't charge you a restocking fee if you exchange them within 15 days. And to answer your question, it makes no difference. The motherboard chipset determines the type of ram you can run, and the qvL gives you only a few examples of tested ram.